To Have Mass And Not To Have Mass revisiting relativity

[mitchellmckain 0]

Everything in this world is one of two types: those which have mass like the electron and those which have no mass like the photon (light).Electrons have mass so they always travel less than the speed of light and have kinetic energy approaching infinity as their speed approaches the speed of light. Since velocity is relative this means that the energy of the electron also depends on how fast you are moving, but because it has mass, if you have exactly the same velocity as the electron, so that relative to you it is not moving at all, the electron has no kinetic energy but it still has energy called its rest mass energy.Photons have no mass so they always travel exactly at the speed of light. However the energy of the photon also depends on how fast you are moving. As you approach its velocity (being massive you cannot reach that velocity), its velocity relative to you does not change (the relative velocity remains the speed of light), but the energy of the photon decreases towards zero (no energy at all). This may sound a bit puzzling for if the relative velocity between you and the photon never changes as you "approach its velocity" then what does "approach its velocity" mean? Well by "approach its velocity" I basically mean accelerating in the direction of its motion. There is no effect on the relative velocity between you and the photon but only on the energy or wavelength of the photon, and is otherwise known as redshift. The wavelength increases and the energy decreases.

[mustra 0]

Everything in this world is one of two types: those which have mass like the electron and those which have no mass like the photon (light).
Electrons have mass so they always travel less than the speed of light and have kinetic energy approaching infinity as their speed approaches the speed of light. Since velocity is relative this means that the energy of the electron also depends on how fast you are moving, but because it has mass, if you have exactly the same velocity as the electron, so that relative to you it is not moving at all, the electron has no kinetic energy but it still has energy called its rest mass energy.

Photons have no mass so they always travel exactly at the speed of light. However the energy of the photon also depends on how fast you are moving. As you approach its velocity (being massive you cannot reach that velocity), its velocity relative to you does not change (the relative velocity remains the speed of light), but the energy of the photon decreases towards zero (no energy at all). This may sound a bit puzzling for if the relative velocity between you and the photon never changes as you "approach its velocity" then what does "approach its velocity" mean? Well by "approach its velocity" I basically mean accelerating in the direction of its motion. There is no effect on the relative velocity between you and the photon but only on the energy or wavelength of the photon, and is otherwise known as redshift. The wavelength increases and the energy decreases.

eisntein proved that photosn had mass, no matter youre poiting a flash light from a moving car or youre stood still, the light reaches the wall at the same time.

youre wrong

ps: time is real, time has mass and age, if you take 2 atomic watches, set them up at the same time, send one to space, when it comes back it comes back late, cientists cant explain this but they have done theses experiments.

you live longer in space.

[mitchellmckain 0]

eisntein proved that photons had mass,

Einstein proved that mass was a form of energy but he never said that photons have mass. He developed a superior theory of gravity where a stress-energy tensor (computed from the energy and momentum densities and flux in space) causes a curvature in space time. Since photons have momentum they contribute to the stress-energy tensor and thus to the curvature of space-time. The curvature of space time alters the path of objects (including photons) from that predicted by Newtonian physics which assumes that space is flat or Euclidean.

no matter youre poiting a flash light from a moving car or youre stood still, the light reaches the wall at the same time.

That is quite correct. Or to put it more clearly, if you are racing past a standing person at half the speed of light towards a wall and if you and the standing person shine a flashbulb towards the wall exactly when you are passing the standing person (and thus when you are both the same distance from the wall) then both you and the standing person will agree that the light from both flash bulbs reach the wall at the same time. This is inspite of the fact that both you and the standing person also see the light from both flash bulbs travel exactly at the speed of light away from you toward the wall, which clearly means that it takes a shorter time for the light to reach the wall (.5775 times shorter in fact) according to you compared how long the standing person thinks it takes the light to travel towards the wall.

youre wrong

Wrong about what? What I explained above is from Einstein's theory. Obviously my post has explained some elements of relativity that are new to you. Much of relativity is difficult for the non-physicist to understand. I hope that by clearing up those points where you feel I am "wrong" you will come to understand relativity better.

ps: time is real, time has mass and age

excuse me?

if you take 2 atomic watches, set them up at the same time, send one to space, when it comes back it comes back late, cientists cant explain this but they have done theses experiments.

Yes they have done this experiment and it was a verification of Einstein's Special and General theories of Relativity, so you are very wrong in thinking that scientists cannot explain this. They expected it. Also you got it backwards the clock that went into space was early not late.

[quote name='mustra'" data-cid="78595" data-date="May 19 2006, 01:01 PM">

you live longer in space.

Because more time is passed on the clock that went into space, you would acually live less long in space.

Of course this really is an unwarranted conclusion because that involves more than just physics, but also studies of the effect of long exposures to the free fall environment.

Furthermore, whether more time passes on the clock that goes into space or less time depends on how fast the rocket carrying the clock travels during the trip. You see there are two factors in time dilation. There is the lesser gravity which makes time "run faster" and there is moving at a velocity which is a significant portion of the speed of light will make time "run slower." So if you go away from the earth at a high enough velocity then when you return less time will have passed for you than for those left behind on earth. In fact at 86.6% of the speed of light during the whole trip will mean that the time that has passed for the passengers will be about half the time that has passed for those left on earth.
Edited May 20, 2006 by mitchellmckain (see edit history)

[twitch 0]

Everything in this world is one of two types: those which have mass like the electron and those which have no mass like the photon (light).

Just in this world? OR everywhere?

Photons have no mass so they always travel exactly at the speed of light.

Black-holes spaghetify or bend light. How can the photons be bent if they are traveling at a constant speed? The inward speed of light must be faster than the outward speed of light, otherwise it wouldn't bend.
To be truly honest, this may go against most people's beliefs and foundations, but I don't agree with what Einstein says. Well, not all of it anyway. I just don't understand how one person could rattle off so much 'insight' into the mechanics of the universe.

His famous e=mc(2) was found to be missing one key component. Whether it was + or - (e=+mc(2) or e=-mc(2) ). By algebraic default, the equation should read e=+mc(2) where in fact, for mass (electrons) it should be e=-mc(2).

[mitchellmckain 0]

Just in this world? OR everywhere?

every part of existence that we can measure

Black-holes spaghetify or bend light. How can the photons be bent if they are traveling at a constant speed? The inward speed of light must be faster than the outward speed of light, otherwise it wouldn't bend.

But space itself is curved near a large mass. Consider this question what is a straight line on the surface of an hourglass? So in Einstein's theory the idea of the straight line is replaced with something called a geodesic. Light always follows a geodesic which is the closest you can get to a "straight line" in curved space.

To be truly honest, this may go against most people's beliefs and foundations, but I don't agree with what Einstein says. Well, not all of it anyway.

Oh I do not doubt it. Many people put much more faith in Star Trek than in physics these days because it is so much more fun and easier to understand, even if it is complete nonsense.

I just don't understand how one person could rattle off so much 'insight' into the mechanics of the universe.

Mostly it is just timing and rattling off is not an apt description of what happens. When enough people lay the groundwork in developing new mathematics, finding discrepancies with old theories in physical measurements, and looking at things in new ways. Then just at that time a smart and creative person can put it all together and make a great leap forward in our understanding of things. But even then it is not finished. Because hundreds of scientists and educators come afterwards filling in details, applying the ideas to more circumstances, and testing them in new ways. So what may seem like the work of one man is really the work of many. Relativity is not the unsubstatiated opinion of one man but the checked and double checked theory of the whole scientific community.

His famous e=mc(2) was found to be missing one key component. Whether it was + or - (e=+mc(2) or e=-mc(2) ). By algebraic default, the equation should read e=+mc(2) where in fact, for mass (electrons) it should be e=-mc(2).

NO, this is not correct. For the electron, it is also E = m c^2. E is energy and energy can never be negative nor can m which is the mass. Even antimatter is still posititve energy and positive mass. So the equation E = - m c^2 is impossible and cannot apply to anything.

Now there are more general equation which are a part of his theory, such as
E = gamma m c^2
where gamma = 1/sqrt(1-v^2/c^2) is the Lorentz contraction factor which is 1 when an object is not moving and approaches infinity when the object approaches the speed of light. Whereas E in the other equation is just the rest mass energy of an object this E is the total energy including kinetic energy of the object. At a velocity of 86.6% of the speed of light, gamma = 2, so the energy of an object is doubled. That is at 86% of the speed of light the object has a kinetic energy equal to its rest mass energy.

Another more general equation is
E^2 = m^2 c^4 + p^2 c^2
and like the previous equation this is the total energy including both rest mass energy and kinetic energy, but where the previous equation only applies to object with mass, this equation also works with objects which are massless. For the photon m = 0 but p = hv/c (Plank's constant times the frequency divided by the speed of light) so putting this in the above equation we get E = hv for the photon. You may know that from mathematics that you should also the solution E = - hv, but such solutions don't necessarily have any meaning and it doesn't have any meaning in this case.
Edited May 21, 2006 by mitchellmckain (see edit history)

[Elzear 0]

eisntein proved that photosn had mass, no matter youre poiting a flash light from a moving car or youre stood still, the light reaches the wall at the same time.
youre wrong

ps: time is real, time has mass and age, if you take 2 atomic watches, set them up at the same time, send one to space, when it comes back it comes back late, cientists cant explain this but they have done theses experiments.

you live longer in space.

Oh my i think this topic is to deep for me i better log out now.

[BitShift 0]

Ok so what about this.I heard that once an object reaches the speed of light, it becomes light itself. ( Correct me if I'm wrong ) , and just so you know, my whole question is based on that assumption.Now that I have said that.Lets say we have an object with a positive mass. This object speeds up by some force and eventually reaches the speed of light. Now that it has reached the speed of light it has become light itself.Now, since light cannot have mass, where would the mass of this object have gone? Wasn't it Einstein that said mass could not be created nor destroyed?Or does the light actually have mass. Or maybe all the mass turned into energy, which would be displayed in wavelengths of the light, which would make the light different colors for different amounts of mass or something.Once the object slows down below the speed of light, does it regain its mass and its original properties?I don't know, and one of you guys probably know an answer, or a good explanation.This is one of those things that have always been stuck on my mind but never really found someone to answer it.

[mitchellmckain 0]

Ok so what about this.
I heard that once an object reaches the speed of light, it becomes light itself. ( Correct me if I'm wrong ) , and just so you know, my whole question is based on that assumption.
Now that I have said that.

Lets say we have an object with a positive mass. This object speeds up by some force and eventually reaches the speed of light. Now that it has reached the speed of light it has become light itself.

No. That is impossible. Either something has mass and it can never reach the speed of light or it is massless and is always at the speed of light.

Now, since light cannot have mass, where would the mass of this object have gone? Wasn't it Einstein that said mass could not be created nor destroyed?

Something with mass that was (impossibly) accelerated to the speed of light would have infinite energy (impossible) and I have as much difficulty imagining infinite energy of light as I do supplying infinite energy to accelerate the mass to the speed of light. Very high amounts of energy is very likely to produce mass in pairs of anti-particles but an infinite amount of energy would produce an infinite amount of such mass.

Or does the light actually have mass. Or maybe all the mass turned into energy, which would be displayed in wavelengths of the light, which would make the light different colors for different amounts of mass or something.

Now it is quite possible for mass to turn completely into light as when a proton encounters an anti-proton which competely annihilate likely producing at least two very high energy photons (light).

Once the object slows down below the speed of light, does it regain its mass and its original properties?

Another impossibility. Something at the speed of light could never "slow down." That would be like subtracting numbers from infinity.

I don't know, and one of you guys probably know an answer, or a good explanation.This is one of those things that have always been stuck on my mind but never really found someone to answer it.

My first post already explained all of this.

[green_magi0 0]

Well if photons WERE mass-less then light would be instantanious, but it is not. There MUST be some form of mass to light. Light isa photon but would it not also have electrons in it? If any of my information is wrong please inform me.

[mitchellmckain 0]

Well if photons WERE mass-less then light would be instantanious, but it is not. There MUST be some form of mass to light.

 

Why do you think that?

 

Light travels at the fastest speed possible. The speed of light is our universe's version of instantaneous. Due to time dilation for the object that is traveling at the speed of light it is instantaneous.

 

Light is a photon but would it not also have electrons in it?

 

No, but electrons can produce photons. Accelerate an electron and it radiates photons.